Let's get this math done. We have 409 and we're going to multiply it by 66. This is the same as taking 409 and adding it to itself 66 times.
Step 1: 0 + 409 = 409
Step 2: 409 + 409 = 818
Step 3: 818 + 409 = 1227
Step 4: 1227 + 409 = 1636
Step 5: 1636 + 409 = 2045
Step 6: 2045 + 409 = 2454
Step 7: 2454 + 409 = 2863
Step 8: 2863 + 409 = 3272
Step 9: 3272 + 409 = 3681
Step 10: 3681 + 409 = 4090
Step 11: 4090 + 409 = 4499
Step 12: 4499 + 409 = 4908
Step 13: 4908 + 409 = 5317
Step 14: 5317 + 409 = 5726
Step 15: 5726 + 409 = 6135
Step 16: 6135 + 409 = 6544
Step 17: 6544 + 409 = 6953
Step 18: 6953 + 409 = 7362
Step 19: 7362 + 409 = 7771
Step 20: 7771 + 409 = 8180
Step 21: 8180 + 409 = 8589
Step 22: 8589 + 409 = 8998
Step 23: 8998 + 409 = 9407
Step 24: 9407 + 409 = 9816
Step 25: 9816 + 409 = 10225
Step 26: 10225 + 409 = 10634
Step 27: 10634 + 409 = 11043
Step 28: 11043 + 409 = 11452
Step 29: 11452 + 409 = 11861
Step 30: 11861 + 409 = 12270
Step 31: 12270 + 409 = 12679
Step 32: 12679 + 409 = 13088
Step 33: 13088 + 409 = 13497
Step 34: 13497 + 409 = 13906
Step 35: 13906 + 409 = 14315
Step 36: 14315 + 409 = 14724
Step 37: 14724 + 409 = 15133
Step 38: 15133 + 409 = 15542
Step 39: 15542 + 409 = 15951
Step 40: 15951 + 409 = 16360
Step 41: 16360 + 409 = 16769
Step 42: 16769 + 409 = 17178
Step 43: 17178 + 409 = 17587
Step 44: 17587 + 409 = 17996
Step 45: 17996 + 409 = 18405
Step 46: 18405 + 409 = 18814
Step 47: 18814 + 409 = 19223
Step 48: 19223 + 409 = 19632
Step 49: 19632 + 409 = 20041
Step 50: 20041 + 409 = 20450
Step 51: 20450 + 409 = 20859
Step 52: 20859 + 409 = 21268
Step 53: 21268 + 409 = 21677
Step 54: 21677 + 409 = 22086
Step 55: 22086 + 409 = 22495
Step 56: 22495 + 409 = 22904
Step 57: 22904 + 409 = 23313
Step 58: 23313 + 409 = 23722
Step 59: 23722 + 409 = 24131
Step 60: 24131 + 409 = 24540
Step 61: 24540 + 409 = 24949
Step 62: 24949 + 409 = 25358
Step 63: 25358 + 409 = 25767
Step 64: 25767 + 409 = 26176
Step 65: 26176 + 409 = 26585
Step 66: 26585 + 409 = 26994

So, 409*66 = 26994